Ok, go into c:\program files\commons files\research in mortion\apploader and open loader.exe.

Do not connect your bold yet, and let it sit at the 507 error screen, now when you get to the COM selection screen, plug in your bold, it will say your PIN after once second or 2, immediatly click Next and it will load the OS of your choice after selecting options you want.

I think this is because when 507 no OS error is there, bold is stuck in continous reboot and doesn't connect to desktop manager correctly. Let us know if it worked. You can also wipe your bold for completely and get 507 error with JL_cmder and load new OS from scratch.

hello,
i have the same 507 error and i have tried everything i've found and nothing, nothing works.

i'm using a BB 8110 and i was updating when all of a sudden appears a message saying it could not connect with the BB, and then the 507 ERROR.

i've tried to install everything again and nothing.
i've used the JL Cmder to wipe the BB and to install everything from scratch and nothing
i've tried your method, and nothing
in all the three atempts when i'm in the midle of the process it stops because it could'nt connect.